As a crack and heroin addict who managed to stop using and then wrote about the experience, I get quite a few letters from the relatives of addicts, and they are all saying the same thing in different ways: how can I help my loved one to change? Like this one from Suzie:

"Hi, Mark. I don't know who 2 turn 2. I read ur book. It made me cry. My son is 19 and on heroin. He's got a drug counsellor at the mo and has tried 2 get off it. He did 4 sessions a week but went back on it. NO ONE SEEMS 2 WANT 2 HELP HIM. He is going on subutex soon and wants 2 get off it. He is such a lovely boy but has got no confidence. I got him on a course and he has been going but feels an outcast with his problems. He is crying out 4 help. I luv him so much but I am scared 4 him. No one seems 2 care. Please help me and Jason. Suzie."

Thanks for writing, Suzie. I've chosen to answer your letter in this column - with your permission and your identities hidden - to highlight the difference between your experience and that of another mother, a member of London's chattering and writing elite. Her son used skunk for a few months when he was a teenager. Sorry if I'm hazy on the facts. I refuse to read her book. I refuse to buy it. And I refuse to name it.

No doubt this spell of teenage drug use was very upsetting for her, but she has publicly defined her son as a drug addict, leaving him stigmatised and reacting to that stigma for the rest of his life.

She claims she did so to help others, but what possible use can her book be to Suzie and the thousands like her who are relatives of serious addicts? Her wails can only draw attention away from the real problem, which is the thousands of young people who are causing misery and harm to themselves, their loved ones and the victims of their crimes by serious long-term addiction.

However, both Suzie and the writer have something in common: addiction is a sickness in the family. When the family is dysfunctional, all its members start to behave in a sick way.

Suzie, you already understand something important - that no one wants to be an addict, no one enjoys it, and every addict wants to stop.

Now understand this: Jason's situation is outside your control. He is lost to you for now, because his only relationship is with his drug. And he's getting that. If he's going to change, then he has to do it himself. You can't do it for him.

I remember how my sister - the only person who still found my company tolerable - asked me to leave her house. She finally said: "I love you, Mark, but I can't stand what you're doing to yourself. Please go." That was the beginning of the long process of recovery for me.

Let's not confuse the actions of the writer mother with my story or yours, Suzie. To you, I'd say be resolute about who you are and where your boundaries are, and make this clear to your son. State where you stand on addictive behaviour.

Do it in a loving way. Yes, it's hard to tell someone you love them and then throw them out, but it's better than telling them you love them so much that you're going to accommodate their intolerable behaviour.

Please take care of yourself. Step outside the power of his drug by meeting your own needs, keeping well, and staying strong. Get support - for instance, from Al-Anon. Maybe you can start Jason on a new journey by pursuing your own needs.

I share your frustration over the quality and quantity of the right care for addicts, and the use of substances like methadone and subutex, and I plan to give that more space in another column. In the meantime, good luck. Yours is the real story here, and let's not forget how many others share it before we get swept away on a tide of middle-class angst.

As for that writer mother, she is a dysfunctional adult who has publicly exhibited her sickness by labelling and criminalising her own son. But perhaps we shouldn't be surprised. That is exactly how society as a whole treats its youth.

• Mark Johnson, a rehabilitated offender and former drug user, is author of Wasted. He now runs a charity that aims to reduce reoffending.